A vertical line that the graph of a function approaches but never touches, where the function's value goes to infinity (or negative infinity).

A function of the form $r(x) = \frac{p(x)}{q(x)}$, where $p(x)$ and $q(x)$ are polynomial functions.

The number of times its corresponding factor appears in the polynomial.

A point where both the numerator and denominator of a rational function are zero. It is a removable discontinuity.

If $x = a$ makes the denominator $q(x)$ zero and the numerator $p(x)$ non-zero, then there's a potential vertical asymptote at $x = a$.

It might indicate a 'hole' in the graph rather than a vertical asymptote.

If the multiplicity of a zero in the denominator is greater than in the numerator, there's a vertical asymptote. Higher difference means faster approach to infinity.

As $x$ approaches a vertical asymptote from the left or right, the function approaches either positive or negative infinity.

One-sided limits approaching a vertical asymptote will tend towards $\infty$ or $-\infty$.

Vertical Asymptotes: Occur when the denominator is zero, and the numerator is non-zero. Function approaches infinity. | Holes: Occur when both numerator and denominator are zero. Represent removable discontinuities.